Navigation systems assist users in locating objects. For instance, navigation systems are used in industrial, aerospace, defense, and medical applications. In the medical field, navigation systems assist surgeons in placing surgical instruments relative to a patient's anatomy. Surgeries in which navigation systems are used include neurosurgery and orthopedic surgery. Typically, the instrument and the anatomy are tracked together with their relative movement shown on a display.
Navigation systems may employ light signals, sound waves, magnetic fields, radio frequency signals, etc. in order to track the position and/or orientation of objects. Often the navigation system includes tracking devices attached to the object being tracked. A localizer cooperates with tracking elements on the tracking devices to determine a position of the tracking devices, and ultimately to determine a position and/or orientation of the object. The navigation system monitors movement of the object via the tracking devices.
Many navigation systems rely on an unobstructed line-of-sight between the tracking elements and sensors that receive tracking signals from the tracking elements. When the line-of-sight is obstructed, tracking signals being transmitted from the tracking elements are not received by the sensors. As a result, errors can occur. Typically, in this situation, navigation is discontinued and error messages are conveyed to the user until the line-of-sight returns or the system is reset. In the medical field, in many instances, the error messages are displayed on a monitor remote from the surgeon making it difficult for the surgeon to notice and remedy the error in a timely manner. This can cause delays to surgical procedures.
As a result, there is a need in the art for navigation systems and methods that quickly identify line-of-sight issues so that they can be resolved without significant delay. There is also a need in the art for navigation systems and methods that help to improve the line-of-sight and reduce possible errors associated with obstructions to the line-of-sight between tracking elements and sensors.